1. Field of the Invention
The invention relates to a vehicle control system of a vehicle, such as an automobile, and particularly relates to a technical field of the vehicle control system that performs control of SOC (State of Charge) of a battery installed on the vehicle.
2. Description of Related Art
One example of this type of system has been proposed which drives a motor for generating electric power by driving an engine while keeping its output at a preset level, so as to charge a battery for driving the vehicle, when the amount of charge of the battery for driving the vehicle is equal to or smaller than a preset threshold value, and the vehicle is stopped. Further, when there is a request for operation of an air-conditioning unit of the vehicle, the system operates the air conditioner by driving the engine while keeping its output at a preset level, so as to prevent the traveling range or distance from being reduced due to reduction of the amount of charge of the battery for the vehicle (see Japanese Patent Application Publication No. 2013-255365 (JP 2013-255365 A)).
In the meantime, idling stop for stopping the engine when the vehicle is temporarily stopped is often carried out, in order to improve the fuel economy performance of the vehicle. When the idling stop is performed, a target value associated with SOC control of the battery is often set so that the SOC will be large enough to cover an estimated quantity of electricity to be consumed, which corresponds to a predicted stop time, for example.
Meanwhile, if an air conditioner (which will be referred to as “A/C” when appropriate) is activated, the engine is restarted even during idling stop (namely, the idling stop is cancelled), so as to drive a compressor, for example.
Therefore, if the target value associated with the SOC control is set according to the predicted vehicle stop time, for example, the amount of charge of the battery may become excessively large, and the fuel economy performance may not be sufficiently improved.